Dissolution Trapping of Carbon Dioxide in Heterogeneous Aquifers

Abstract

The geologic architecture in sedimentary reservoirs affects the behavior of density-driven flow and the dispersion of CO-rich brine. The spatial organization and connectivity of facies types play an important role. Low-permeability facies may suppress fingering and reduce vertical spreading, but may also increase transverse mixing. This is more pronounced when geologic structures create preferential flow pathways through connected facies types. We perform high-resolution simulations of three-dimensional (3D) heterogeneous formations whose connectivity cannot be represented in two-dimensional models consistent with percolation theory. This work focuses on the importance of 3D facies-based heterogeneity and connectivity on advection-diffusion transport of dissolved CO. Because the dissolution of CO and the subsequent density increase of brine are the driving force for gravitational instabilities, we model the phase behavior with the accurate cubic-plus-association equation-of-state, which accounts for the self-association of polar water molecules and the cross-association between CO and water. Our results elucidate how the spatial organization of facies affects the dynamics of CO convective mixing. Scaling relations for the evolution of a global dispersion-width provide insights that can be universally applied. The results suggest that the long-term evolution and scaling of dispersion are surprisingly similar for homogeneous and (binary and multiscale) heterogeneous porous media.

Transport of perfluorocarbon tracers in the Cranfield Geological Carbon Sequestration Project

“…This is consistent with our simulation results, which address a two‐phase flow problem and a more complex system in terms of heterogeneity arising from facies architecture. Fluvial depositional systems clearly have a dramatic impact on solute transport in the subsurface in both single and multiphase flow problems because the preferential pathways account for the majority of mass transport . Recently, Kilgallon et al .…”

“…Carbon Capture and Storage (CCS) is a promising technology to mitigate increasing atmospheric carbon dioxide (CO 2 ) concentrations . Identifying and quantifying the processes that affect CO 2 transport in the subsurface are essential to predict CO 2 residence times and to estimate the storage capacity of a reservoir.…”

Water–rock–CO2 interactions and CO2 storage of Honghe tight oil reservoirs: an experimental and simulation study

“…The state of the injected CO 2 consists of free gas (structural-based storage), capillary gas (residually trapped CO 2 ), dissolved gas (solubility-trapped CO 2 ), and mineralization after water-rock interactions (mineral-trapped CO 2 ). Soltanian et al, 15 Kopp and co-workers, 35 Doughty et al, 36 Krevor et al, 37 and Juanes et al 17 have investigated the factors of different CO 2 storage types. In this paper, we focus on the evolution of different CO 2 storage types during CO 2 flooding in the target tight oil reservoir.…”

“…Many factors, such as geologic characteristics, 15,16,39 salinity, 14 permeability, 17 and water-rock interactions, 18,19 significantly influence the CO 2 storage. Recent studies [18][19][20][21][22] focus on the impact of CO 2 -water-rock interactions on CO 2 storage.…”

An approach to predict the height of fractured water-conducting zone of coal roof strata using random forest regression

“…The group method of data handling (GMDH)-type neural network does not need the preset network structure, and the classification rules are expressed by some simple polynomials. However, the GMDH training algorithm can obtain good results only in the case that the noise and interference are distributed by Gaussian, otherwise, the training algorithm often overfits the network 30,31 . In the current study, RFR was used to predict the height of FWCZ.…”